1. Field of the Invention
The present invention relates to a plasma display panel (hereinafter, PDP), and more particularly, to a PDP with a barrier rib structure which is defined independently for each discharge cell by barrier ribs formed between two substrates.
2. Description of the Related Art
Generally, a plasma display panel is a display device in which ultraviolet rays generated by gas discharge excite phosphors to realize predetermined images, and it has been spotlighted as a candidate for wide screen display devices since it enables production of large screen sizes with high resolution.
A generally known PDP is formed with address electrodes along one direction (in the X-axis direction of the drawing) on a rear substrate, and a dielectric layer is formed on an entire surface of the rear substrate covering the address electrodes. On the dielectric layer, barrier ribs of a stripe pattern are formed between each of the address electrodes, and red R, green G, blue B phosphor layers are formed in valleys between each of the barrier ribs.
In addition, display electrodes having a pair of transparent electrodes and bus electrodes are formed along the direction crossing the address electrodes (in the Y-axis direction of the drawing) on a surface of a front substrate opposing the rear substrate. A transparent dielectric layer and a MgO protective layer are formed covering the display electrodes on an entire surface of the front substrate.
The region where the address electrodes on the rear substrate intersect the display electrodes on the front substrate is a portion where discharge cells are formed.
An address voltage Va is applied between the address electrodes and the display electrodes to cause address discharge, and a sustain voltage Vs is applied to a pair of the display electrodes to cause sustain discharge. Then, generated vacuum ultraviolet rays excite phosphors so that they emit visible light through the front substrate and thereby display PDP images.
However, the PDP having the display electrodes and the barrier ribs of the stripe type, may cause crosstalk between the discharge cells adjacent to the barrier ribs. In addition, it may cause a mis-discharge between the adjacent discharge cells since the discharge spaces are connected to one another along the direction where the barrier ribs are formed. In order to prevent these problems, the distance between the display electrodes corresponding to the adjacent subpixels has to be greater than a certain level, which causes a reduction in improvement of efficiency.
To solve the above problems, the PDPs having improved electrodes and barrier ribs have been suggested.
That is, the PDP has barrier ribs of the stripe type, but a transparent electrode of display electrode has a shape such that it is extended from bus electrode to face each other in a pair within each discharge cell. U.S. Pat. No. 5,640,068 issued to Amemiya for Surface Discharge Plasma Display discloses a PDP related thereto.
However, even the PDP with the above structure cannot solve the mis-discharge along the direction of the barrier ribs mentioned above. For the purpose of solving this problem and enhancing the emission efficiency, a PDP is suggested which has barrier ribs of the matrix type formed with vertical barrier ribs and horizontal barrier ribs being perpendicular to each other. Japanese Laid-Open Patent No. 1998-149771 issued to Yatsuda, et. al., for Plasma Display Panel and Manufacture Thereof discloses a PDP related thereto.
In the PDP having the stripe type barrier ribs or the matrix type barrier ribs, as most areas except at the barrier ribs are designed as discharge spaces, the display electrodes pass over the discharging space so that opaque bus electrodes thereof obstruct the transmission of some visible light generated by gas discharge, thereby reducing the brightness.
Furthermore, in order to prevent the mis-discharge along the vertical direction, the distance between display electrodes corresponding to the adjacent discharge cells has to be over a certain level, which becomes a limiting factor for manufacturing a high resolution PDP.
Moreover, although technology is suggested which has black pigment bands between the adjacent discharge cells along the vertical direction in order to improve the contrast, it may limit achievement of high resolution since a predetermined width between display electrodes is required.